Article Figures & Data
Figures
- FIG. 1.
TCRα/β+ T cells are required for host protection. BALB/c TCRβ−/− (n = 12) or BALB/c wt mice (n = 9) were injected i.p. with 50 B. malayi L3 infective-stage larvae. At 6 weeks postinfection the animals were necropsied, and live parasites were recovered from peritoneal lavage. Data are shown as a percentage of the initial inoculum recovered as viable parasites at the time of necropsy. The P value between wt and TCRβ−/− mice is 0.024. The error bars represent the standard error of the mean (SEM).
- FIG. 2.
IL-4, IL-4R signaling, and Stat6 are all required for murine host protection (A) BALB/c IL-4−/− mice (n = 5), BALB/c IL-4R−/− mice (n = 4), or BALB/c wt mice (n = 5) were injected i.p. with 50 B. malayi L3 infective-stage larvae and then necropsied at 12 weeks postinfection. Live parasites recovered from peritoneal lavage were quantified and are expressed as a percentage of the original infective dose. The P values between wt and IL-4−/− mice or between wt and IL-4R−/− mice are 0.001 and 0.020, respectively. (B) BALB/c wt (n = 5), IL-4−/− (n = 5), or Stat6−/− (n = 5) mice were injected i.p. with 50 B. malayi L3 infective-stage larvae and sacrificed 6 weeks postinfection. The P values between the recoveries from wt and IL-4−/− mice or between wt and Stat6−/− mice are 0.002 and 0.001, respectively. The data are shown as the percentage of the initial inoculum recovered as viable parasites at the time of necropsy. The error bars represent the SEM.
- FIG. 3.
IL-4−/− T cells are sufficient to mediate significant host protection. CD19-depleted splenocytes from naive BALB/c wt or BALB/c IL-4−/− donors were transferred into BALB/c TCRβ−/− recipients (n = 5) 3 days prior to i.p. infection with B. malayi L3. Control TCRβ−/− animals received naive CD3-depleted splenocytes from IL-4−/− donors. (A) Anti-CD3 and anti-CD19 staining of depleted cell populations prior to adoptive transfer. (B) Anti-TCRβ and anti-CD19 staining of PEC recovered at the time of necropsy. Total PEC are gated on lymphocytes. (C) Animals were sacrificed 6 weeks postinfection. The data are shown as the percentage of the initial inoculum recovered as viable parasites at the time of necropsy. The P value between control TCRβ−/− mice and recipients of CD19-depleted wt cells and between control animals and recipients of CD19-depleted IL-4−/− cells is 0.003 for both comparisons. The error bars represent the SEM. The P value between recoveries from unmanipulated wt and IL-4−/− mice is 0.004.
- FIG. 4.
SCID recipients of wt, Stat6−/−, or IL-4R−/− T lymphocytes are equally well protected. (A) Anti-CD3 and anti-CD19 staining of PEC recovered at time of necropsy of recipient mice. The plots represent total PEC gated on lymphocytes. (B) Total splenocytes from naive wt or Stat6−/− mice were transferred to SCID recipients (n = 7 to 10) prior to infection with B. malayi. The data are shown as the percentage of the initial inoculum recovered as viable parasites at 6 weeks postinfection. The solid bar represents BALB/c SCID animals receiving a control injection of PBS. The P values between unreconstituted SCID mice and those receiving wt cells and between unreconstituted animals and recipients of IL-4R−/− cells are 0.001 and 0.002, respectively. The error bars represent the SEM. (C) Total splenocytes from naive wt or IL-4R−/− mice were transferred to SCID recipients (n = 20) prior to infection with B. malayi. Ten mice from each cohort were sacrificed each at 6 and 10 weeks postinfection. The data are shown as a percentage of the initial inoculum recovered as viable parasites at the time of necropsy. The P value between unreconstituted SCID mice and those receiving wt cells is <0.001, and the P values between unreconstituted mice and recipients of IL-4R−/− cells are <0.001 and 0.001. The error bars represent the SEM.
- FIG. 5.
Eosinophil recruitment requires T cells and IL-4R expression by nonlymphocytes. (A) Representative plots of PEC isolated at 6 weeks postinfection from a wt or TCRβ−/− mouse and from a TCRβ−/− recipient of CD19-depleted splenocytes from a wt donor. (B) Representative plots of PEC isolated at 6 weeks postinfection from an IL-4R−/− or SCID mouse and from a SCID recipient of splenocytes from an IL-4R−/− donor. Circles denote eosinophil population.
Tables
- TABLE 1.
Ex vivo IL-4 production by PEC from BALB/c wt micea
Day postinfection Fraction % T cells Mean IL-4 concn (pg/ml) ± SD with: Medium alone Medium + ionomycin NAb (PBS control) Whole PEC 4 3 ± 5 35 ± 47 7 Whole PEC 5 85 ± 23 733 ± 58 Thy 1.2+ 17 220 ± 113 1,500 ± 0 Thy 1.2− 0.3 20 ± 8 91 ± 33 14 Whole PEC 3 30 ± 13 140 ± 26 Thy 1.2+ 10 74 ± 1 450 ± 71 Thy 1.2− 0.3 13 ± 14 80 ± 0 ↵a PEC were recovered by peritoneal lavage from PBS-injected or L3-infected wt mice (n = 5) at days 7 and 14 postinfection. Equal total cell numbers of whole PEC, Thy 1.2-depleted, or Thy 1.2-enriched populations were cultured in the presence or absence of ionomycin as described in Materials and Methods. The cellular composition before and after separation was determined by CD3 staining for T cells and by intermediate Gr-1 staining and forward scatter-side scatter properties for eosinophils. IL-4 was measured from culture supernatants by sandwich ELISA as described in the text and is expressed as an average of multiple wells ± the standard deviation. (Six wells were analyzed for whole PEC samples, 11 wells for were analyzed Thy 1.2-depleted samples, and 2 wells were analyzed for Thy 1.2+ samples.)
↵b NA, not applicable.
- TABLE 2.
Eosinophil numbers in control and reconstituted animalsa
Animal group Total no. of eosinophils (106) Mean cells per mouse ± SD IL-4R−/− mice 0.1, 0.12, 0.93, 0.65, 0.36 0.43 ± 0.36 SCID mice recipients of IL-4R−/− lymphocytes 0.89, 2, 1.1, 1.3, 0.8, 0.7, 1.6, 1.6, 1.6 1.28 ± 0.45 ↵a BALB/c SCID mice were reconstituted with total splenocytes from wt or IL-4R−/− donor animals prior to infection with B. malayi as in Fig. 5B. Total numbers of eosinophils were determined on the basis of their distinctive size and granularity profile as previously described (34, 40). Thus, T cells, even from IL-4R−/− mice, are able to reconstitute the ability of the recipient mice to recruit eosinophils to the peritoneal cavities in response to B. malayi infection.
